Life preserver cushions have long been used in boats. Some as exemplified by the patent to Golding U.S. Pat. No. 65901 and Wood U.S. Pat. No. 264814 are designed to be connected together and can form a raft sufficient in size to support a number of persons and to carry emergency provisions.
Typically the life preserver cushions have a buoyant polyethelene foam core positioned inside a surrounding cover of water impervious material. When not used in an emergency situation they serve as cushions on the boat. The advantage of this use is that they are kept above deck so that in an emergency they can, as exemplified by the patents cited above, be connected together and thrown in the water where they can support a number of persons.
The advantage of using floatation cushions that can be connected together is that in an emergency situation the people in the water clinging to the connected cushions will stay together where they can help each other, and they will be more visible. Consequently, they can be more easily found be searchers, than a single person holding on to a single seat cushion.
However emergencies can happen very fast, and when a boat has to be abandoned there may be no time to gather emergency supplies.
There may be only enough time to abandon ship and cling to the cushions. Once in the water the persons clinging to the cushions may be able to connect the cushions together.